• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.183-191
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• 1999

In the recirculating hydroponics, pH of nutrient solution was gradually decreased until the middle of growing-period, and then began to go up and reached the initial level at the latter of growing-period regardless of Cu·Zn content. Changes of pH was gently down for supply of humus in nutrient solution. The growth of lettuce was good with supply of humus, but it was decreased as Cu·Zn content was increased. Although leaf chlorosis was caused by excessive content of Cu·Zn as 5, 10 ppm, it was controlled by adding humus in nutrient solution, and fresh weight of lettuce was obviously improved by adding humus.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.364-369
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• 2005

In Jeju island, the southernmost island of Korea, the field soils are mostly consisted of volcanic and non-volcanic soils. Animal manures of 0, 50, 100, and 150 MT/ha were treated to analyse the humus content changes by application amounts and the soil types. The results are as follows; Humus distribution type was A in the most of the volcanic soils while a few soils was type B, and it was possible to confirm that the humus process has occurred in the soils. Most of the non-volcanic soils was Rp and B type, therefore, the humus content change pattern was different from the volcanic soils. The nitrate-nitrogen content and the humus content showed positive correlation of $R^2=0.5263$ in the volcanic soils, while that of non-volcanic soils was $R^2=0.524$. The carbon content and the humus content showed positive correlation of $R^2=0.469$ in the volcanic soils, while that of non-volcanic soils was $R^2=0.550$.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1998.10a
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• pp.88-91
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• 1998

최근 급속한 산업발달로 인하여 환경오염이 날로 심화되고 있으며, 특히 재배적인 측면에서 토양이나 수질의 중금속오염 문제가 크게 우려되고 있다. 이 중 Cu와 Zn은 식물체의 탄수화물이나 단백질 합성 및 여러 가지 효소 작용에 필수적인 원소이지만 그 양이 과다하면 철 결핍 증상과 비슷한 잎의 황화(chlorosis)현상을 일으킨다. 한편, humus내에 함유되어 있는 humic acid는 양액에 첨가하면 다가의 양이온과 결합하여 난용성 염을 형성하고 (중략)

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.172-182
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• 1999

Leaf lettuce(Lacaug sativa L.) was cultivated in deep flow culture to investigate growth and yield in relation to different reusing method of nutrient solution after once cultivation. Five different treatments were allocated to the nutrient solutions - Control(total renewal of solution), NSS(nutrient solution supplement), U control, NSAC(nutrient solution analysis and compensation), NSAC and Humus supply(NSAC with supply of Humus). The pH of solution was kept stable below 7.0 during 4 successive culture in NSAC and NSAC and Humus supply. U was sharply declined in NSS as the number of cultivation was increased. Gmwth and yield of NSAC was similar to those of Control because nutrient elements were kept the balance to the better growth, while the lettuce grown in NSS and EC control was shown lower growth rate. In the nutrient solutions, Content of N $O_3$-N and N $H_4$-N were remarkably decreased after the cultivation in all treatments. Ca and Mg were shown to be accumulated in nutrient solution regardless of culture times and treatments. After the first culture in NSAC and Humus supply, total N and P$_2$ $O_{5}$ content in leaves were lower than any other treatments, but Ca content was higher. Those were not significant as following cultures, and no significant difference of K and Mg content were shown among the treatments.

• Journal of the Korean Chemical Society
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• v.19 no.4
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• pp.258-268
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• 1975

The physical and chemical characteristics of solid organic wastes from paper and pulp industries, tanneries, and food processing industries were studied with regard to fertilizer value as well as humus sources as a rational method of waste utilization. The pulp and paper mill wastes containing low mineral nutrients but high lignin may be utilized for soil amendments through humus preparation. Chemical treatment sludges of tannery wast water contained appreciable fertilizer nutrients andiliming materials, but utilization as fertilizers or soil amendments depends on the pollution effect of high chromium content, which has not been well understood. Food processing wastes may be utilized as organic fertilizers or micronutrient sources for plant. Some wastes containing high water-soluble sugars or lower C/N ratio than 20 may be utilized as additives for rapid humus preparation.

• Journal of Environmental Impact Assessment
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• v.7 no.2
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• pp.5-14
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• 1998

This study was performed to estimate interrelation between characteristics of sediment and nutrient releare from sediment in Dae-cheong lake. For the investigations, sediments were sampled in June and October 1997 at fish farms, embayment, and the main stream of Dae-cheong lake. Items for investigation are as follows; water content, weight loss on ignition(IG), porosity of sediment, Total Kjeldahl Nitrogen(TKN), content of element(H, N, C), nutrient release rate. Water content and porosity were measured to conjecture the physical trait and grain size. And weight loss on ignition was measured to determine the contents of organic substance. For the determination of nutrient release rate, $PO_4-P$ and $NH_4-N$ concentration of interstitial water and overlying water were measured. Release rate of nutrients which has direct influenced upon the water quality were 0.05-8.63mg-$P/m^2{\cdot}day$ and 4.99-36.56mg-$N/m^2{\cdot}day$. And it was found that release rate was measured higher in the 1st sampling than in the 2nd sampling. And for determination of the humus level of sediment, carbon and nitrogen content were measured by using elemental analyzer. Generally, C/N ratio is used to determine humus level of lake sediment. As a result of elemental analysis, C/N ratio was determined in the range of 7.64~11.55, so humus level of Dae-cheong lake sediment was estimated from mesohumic state to oligohumic state.

• The Korean Journal of Ecology
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• v.8 no.2
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• pp.81-87
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• 1985

The vegetation on the north and south slopes of Kwanak mountain was assessed and recorded during thesummer of 1976. Recordings were made of 5*5m quadrats placed along the transects running parallel to the slopes. On the north slope, most of large trees such as Alnus sibirica, Sorbus alnifolia, Robinia pseudo-acacia and Pinus rigida make the crown and their mean DBH was conspicuously large, while the vegetation of south slope is dominated by dwarf Juniperus utilis, Pinus densiflora, Weigela florida var. glabra which are considered as a resistant species of dry site. The amount of humus, total nitrogen, soil water content and available phosphorous is higher on the north slope than the south one. However, the soil pH is higher on the south slope. It is assumed that the humus content is a main factor to make difference on the type of vegetation between the north and south slope.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.171-176
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• 1985

The structure of natural vegetation and soil condition in bog area of Woopo, Changnyeung, South Korea were observed. The vegetations in the investigated area could be classified into two groups; a typical bog vegetation with dominant species of Eleocharis mamillats, Acorus calamus and Persicaria hostatosagittata and the transitional vegetation of three neighboring areas. Interspecific correlation in the investigated area was very close. In the typical bog vegetatiion regions (region II, III, V, VI, VII, VIII and X) soil pH, field moisture capacity, available P content and exchangeable K were moderate. But, In the transitiional area I, with the highest humus content, field moisture capacity and exchangeable K Salix gracilistyla was dominant. In the region IV with the lowest humus and a ailable P content and with high soil pH Geophyta was a major component species. Also Acorus region IX with the lowest content of exchangeable K Therophyta was dominant and plant species was diverse due to weak water influence. The vegetation structure of the region IX was most different from that of the whole vegetation.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.2
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• pp.169-179
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• 1998

This paper was performed to estimate interrelations between humus level of sediments and nutrient release from sediments in Dae-cheong reservoir. For investigations, sediments were sampled in June and October, in 1997 at fish farms, embayment, and the main stream of Dae-cheong reservoir. Items for investigation are as follows; water content, weight loss on ignition(IG), porosities of sediments, contents of element such as hydrogen, nitrogen, carbon, and nutrient release rates. Water contents and porosities were measured to conjecture the physical trait and grain size trait. Weight loss on ignition was measured to determine the contents of organic substance. For determination of the humus level of sediments, carbon and nitrogen contents were measured by elemental analyzer. As a result of elemental analysis, C/N ratio was determined in the range of $3.0\~13.1$. From the elemental analysis, humus level of Dae-cheong reservoir sediment was estimated from mesohumic state to oligotrophic state. For the determination of nutrient release rate, $PO_4-P$ and $NH_4-N$ concentrations of interstitial water and overlying water were measured. By using the concentration difference between interstitial water and overlying water and using the Fick's diffusion law, the release rates of phosphorus and nitrogen from the sediment samples were calculated. Release rates of nutrients which directly influence to the water quality were $0.05\~8.63mgP/m^2day$ and $4.99\~36.56mgP/m^2day$. It was found that release rate was measured higher in the 1st sampling period than in the 2nd sampling period. For the determination of phosphorus content in sediment, TPs were measured in 807\~1542{\mu}g/g$ in the 1st samling period and $677\~5238{\mu}g/g$ in the End samling period. Phosphorus release rate and phosphorus content were not interrelated each other.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.3
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• pp.113-119
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• 1975

Volcanic Ash Soils are widely distributed in Jeju island, and constitute the important upland soils which are either presently being cultivated or are suitable for reclaiming. The characteristics of Volcanic Ash Soils according to data made available by previous studies in Jeju and the outside of the country are as following: The most conspicuous mineralogical property is the presence of amorphous mineral colloids. The colloids have large and highly reactive surface to which the common physical and chemical properties are related. Soils are low in bulk density and higher both in porosity and permeability. Accumulation of humus in the upper part of soil is found in great quantity. Cation exchange capacity is high mainly due to high humus content, but the absorbing intensity of ammonium and potassium is weaker than that of crystalline clays. The phosphate absorption coefficient is extremely high and deficiency of minor element may occur both crops and animals. Soils are densely populated with actinomycetes and anaerobic bacteria. Nitrification and activity of urease are distinctly stronger than that of non-Volcanic Ash Soils.